The European Health Insurance Card, (EHIC), includes treatment of pre-existing medical conditions and routine maternity care it does not cover if travelling abroad for specific treatment. It is not valid for private healthcare or mountain rescue in ski resorts or cruise ships.
EHIC should not replace travel insurance which would help to recover services and treatments outside the standard remit such as air ambulance and repatriations from European destinations.
The EHIC is free for British citizens and ordered from gov.uk/European-health-insurance-card
Full details are given for each country on the healthcare abroad site www.nhs.uk
A recommended guide for the best buys on travel insurance take a look at www.telegraph.co.uk/tt-travelinsurance